Device for separating particulate material from a mixture of particulate material and fluid

ABSTRACT

A centrifugal dust-from-air separator in which an upright cylindrical casing has mutually opposed nozzles on each end which project into the casing through opposite end walls and are convergent towards the interior of the casing. A guide member extends along the axis of the casing and enters the mouth of the nozzles so that swirling air and dust mixture entering one nozzle induce a secondary recirculating airflow in the casing, dust moving into the secondary flow under centrifugal force and being deposited at the lower end of the casing and clean air leaving by way of the upper nozzles.

United States Patent l l I Inventor Antony D. Cameron Aberdeen, England Appl. No. 886,462 Filed Dec. 19, 1969 Patented July 20, I971 Assignee Aberdeen Engineering Design Limited Aberdeen, England Priority May 3, I967 Great Britain 20,435/67 Continuation-impart of application Ser. No. 725,868, May I, 1968, now abandoned.

DEVICE FOR SEPARATING PARTICULATE MATERIAL FROM A MIXTURE OF PARTICULATE MATERIAL AND FLUID 2 Claims, 4 Drawing Figs.

US. Cl 55/338, 55/457 lnt.Cl 801d 45/12 55/338,

Field of Search 447,458-460; 209/21 1, l44;2l0/5l2 Primary Examiner-Frank W. Lutter Assistant Examiner-Bernard Nozick AnorneyMason, Fenwick & Lawrence ABSTRACT: A centrifugal dust-from-air separator in which an upright cylindrical casing has mutually opposed nozzles on each end which project into the casing through opposite end walls and are convergent towards the interior of the casing. A guide member extends along the axis of the casing and enters the mouth of the nozzles so that swirling air and dust mixture entering one nozzle induce a secondary recirculating airflow in the casing, dust moving into the secondary flow under centrifugal force and being deposited at the lower end of the easing and clean air leaving by way of the upper nozzles.

i fl i l ll PATENTED JULZO |97| SHEET 1 BF 3 lnvenlor ANTONY Duncan CAMERON y W) (1.3% E 8 PATENTED JULZO m SHEET 3 [IF 3 igamwm A Home y 3 t -More particularly,-the

a navicssoii slim-mm rearm-notion' 2 "M AMIXTURI: or nnricrunn m n This invention relates' to a device foruse in separating par ticulate material from a mixture of particulate material and a r fluidr and especially butnot exclusivelyrto the separation of dust from a mixture or dustipart'icles and air, andis a Con tinuationJn-Part of my copending-Pat. application Ser. No.

- 725i868fi|edlMaylLl968 now abandoned.

tie rod extendingbetween the nozzles l7 and l7 '-'and-'con-' .nected-theretobynutstQL I I" 4 f The casing- 10 is providediwith a dust outlet in the form of a tube which is in communication with the interior of thecas- Accordingito the present invention, there-is provided a devicefor use inseparating particulate material-from'amix.

ture of particulate rnaterialand fluid, said device comprising 7 an upstanding cylindrical casing having opposed upperand lowerend walls, tubular nozzles projecting one through each of said end walls having anozzle mouth spaced inwardly from the adjacent end wall of the-casing, at least one of said nozzles delining-a'convergent inletjt tthe casing; aguide member formedl with, a cylindrical external surface a'nd extending on and along: the longitudinal axis .ofithecasing and entering the ing 10 and islocated at one end thereof at the periphery of the closure member .14. The tube '20 is provided with an internal I partition 21 which projects i'nto'the casing 10.

1 In. use, a flow of air containing dust particles is introduced arrow 8. Due to, the offset position of the tube 18, the air/partielej mixture entering the inlet nozzle .17 circulates in one direction aroundthe adjacent end of the tube ll. The circulating mixture is then injected into the casing .10 through the open mouth of theinl et nozzle]? and moves helically through the casing-l0 around the tube 1] which serves to'deline a primary flowpath between the nozzles and to guide the air com mouths ol'the ynozzles' peripherally spaced'therefrom, said,

' cylindrical externalsurface-of said guide: member defining a primary flowpath between said nozzles, an oblique inlet, conduit offset from the :longitudinalaxis of thecasingand conriected m bottom end wall of thenoz'zle defining said convergentinlet for, directing mixture, when flowing into the casing Y through the said one of the nozzles-defining a convergent inlet to the casing; helically around said guide-member and towards pone ntof t'hemixture towards the other end of the casing 10 andto hrthe position of'the vortex of the flow centrally within thecasing' l0. Dust' par'ticlesiare separated from the mixture as a resultofcentrifugal forceunddepositedjat the'lowerend of the casing [0 by a-recirculatory" secondaryairllow which is in- I .ducedby the primary airflow, the air passing on and out of the casing lo through the outlet 13 wherein circulating movement of the air is converted toa straight flow in theoutlet tube 18'.

Where D'isthe diameter of the'exit of the nozzle 17' and d is v thefdiameter ofthatportion' of the tubei l which extends between-the nozzle exitsgthe' preferred relationship between .wall.ofthecasing 'in which saidoneof 'said' nozzles definingsaid convergent inlet extendia nd being positioned adja'centthe cylihdrichl casing whereby; injuse, flow of fluid helically'along said primary flowpath inducesasecondary-flow of fluid'which recirculates from'one end of the casingT to theother end of the I reasing-between" the primary flow and the casing,". particulate *material moving under centrifugal force from the primary flow to thesecondary'flow and being deposited at the lower end of --t'hecasing."i 1 t m o m ml amines byi 'a in'which: JFK}; l is a 'sectlonal elevationof-adevice according'iq the present invention,. t f r 1 FIG; Z'is a view'in the direction' ofarrow A in FIG. I. t

example, with reference to the drawings' ing amodilication, and" 51-10.; is'a sectional elevation similar to FlG I Q-but an- 1 I, l of vanes adapted and arrangedbto present 'a minimum resistanceto fluid flow. within the device and serves to ensure a r FIG. is a section'al elevation similar to FIG. l, but-showing I furthermodifications,

In' FIGS. .l and 2 of the drawings, a device for separating I dust particles from a mixture of dust particles and airconsists *lof an'upstanding cylindrical casing 10, an elongate guide member in-the' formof a closed tube ll, amixtui einlet l2, and an airoutletl3.

and 15 one atfeach endofthe casing-each closuremember I 3 "beings .circula rend wall having an apertureconcentric with.)

the casing 10; The tube 1-] is concentric with the casing 10 and has tapered endportions' 11A each of which terminates in a 1' threadedrod or studio. The inlet 12 and the outlet-l 3 are identical-in construction and consistof hollow frust'oconieal nozzles," and 11 the smaller diameterends or..,-mouths of cnsing l tl has closure members la H aximum) =nxb Theprel'erredminimum internaidiameter'of casing l0is ljtThe deviee abovj described isusedwith its longitudinal axis in an upright position so that'trap'peddustlparticlestend to fall to the'lower end of thez'casing l0, 1where they find an outlet rin sacramental will mwi'be through the tube 2 0.The partition 21 induces a flow of air outwardly through the tube 20,whichflow assists in theremoval of the trapped dust particles from the casing. 10.

A first preferred embodiment-of the invention is shown in FlGr S-in which the same reference numerals are used as in FIG; 1;" but with the addition of .the 'suffixnA'. The device showninFIG. 3 is constructed in themanner described in t respect of FIG. I and, in addition; incorporates a further body or sleeve 22 which isarranged coaxial with the casing'lOA and the tube' llA'; The isleeve may be supported in the position shown in FIG; 3 by means of brackets v(not shown) in the for'm' "desired recirculation within the annular space" formed by the 22 ofFlGjl'but havingflared'end-portionslln Fl(i.4,helical external surfaceofthe sleeve 22 and the internal surface of 'thefcasing 10A over the full length of the sleeve 22. The ends of the sleeve 22 are open andlieadjacent the mouths of the nozzles 17A and 11A;

'A'second preferred embodiment of the invention is shown in FIG. dinwh'ich the same reference numeralsare used as in FIG} I. but with the addition of the suffix B. The device shown in FIG, incorporates a sleeve 22' similar to the sleeve movement of the air/particle mixture is induced by means of which are o'pen and project into the casing ltl through the end: wall apertures. Pipes-l8 and 18' are attached respectively to.

theb'ase's cfthe nozzles l7 and l7and these pipes 18 and I8} communicate with the'interiorslof theassociated nozzles 17 imuin diameter of the guide member] 18 within the inlet'nozand I7. The pipes l8 and i8 are offset from the longitudinal cellinghelical movement of outflowing'air.

angled vanes 23 in an alternative'iniet nozzle 178. The guide member, IB is generally of ,reduced diameter compared with the guide members 11- and 1 1A and includes a tapered portion l l B- adjacent the mouth of the inlet nozzle 17B, the max- 'zle 178 being about two-thirds the: inletnozzle diameter. An alternative outlet nozzle l7B'-incorporates vanes 24 for-can- Using the symbols D and d forthe dimensions discussed with reference to the FIG I embodiment. and where l is'the distance between the nozzle mouths. it has been found I into the icasing It) through the inlet 12 in, the direction of preferable to incorporate the sleeve 22 when l is greater than lfixp. The preferred diameter of the sleeve is equal to Q X D,

Whereas the device first above described (FIGS. 1 and 2) is used with its longitudinal axis upright, the preferred embodiments (FIGS. 3 and 4) are advantageous in that they may be used with their longitudinal axes inclined and, moreover, in that dust particles are collected at the lower end of the casing 10A or lB regardless of whether the air outlet is at the upper or the lower end of the devicev The scope of the present invention is not limited to the above described embodiments, and further modifications may be made. The particle outlet tube 20, A may, for example,

be dispensed with, dust particles being removed from time to time by removing one of the closure members. The outlet assembly need not be identical in construction with the inlet assembly.

The length of the guide member may be chosen in accordance with the size and/or weight of the particles to be separated from the fluid/particle mixture. Relatively lightweight or small particles would require a longer helical path and therefore a larger guide member than would relatively heavy or large particles. Moreover, if desired, the guide member length may be chosen so that only relatively heavy or large particles were separated out while relatively lightweight or small particles were retained in the mixture; for example in the case where particles of different materials were present.

A number of devicesaccording to the present invention may be arranged in parallel in order to provide increased capacity. A device according to the present invention may include a builtin fan or impeller driven by a motor mounted on the device or on an adjacent fixture. The casing may be provided with a door for providing access to the interior of the casing for the purpose of maintenance, including the removal of sticky substances and routine cleaning, painting and inspection.

The embodiments described may be used in applications other than the separation of dust from a mixture of dust and air. For example, particulate chemicals may be separated from gases, or valuable particles may be recovered from an unwanted fluid medium. A device in accordance with the present invention may be used in separating particulate material and a I. A device for use in separating particulate material from a mixture of particulate material and fluid, said device comprising an upstanding cylindrical casing having opposed upper and lower end walls, tubular nozzles projecting one through each of said end walls having a nozzle mouth spaced inwardly from the adjacent end wall of the casing, at least one of said nozzles defining a convergent inlet tothe casing, a guide member formed with a cylindrical external surface and extending on and along the longitudinal axis of the casing and entering the mouths of the nozzles peripherally spaced therefrom, said cylindrical external surface of said guide member defining a primary flow path between said nozzles, an oblique inlet conduit offset from the longitudinal axis of the casing and connected to a bottom end wall of the nozzle defining said convergent inlet for directing mixture, when flowing into the casing through the said one of the nozzles defining a convergent inlet to the casing, helically around said guide member and towards the other nozzle along said primary flow path, the mouths of the nozzles being smaller in diameter than the internal diameter of the casing and relatively small dust outlet in the end wall of the casing in which said one of said nozzles defining said convergent inlet extend and being positioned adjacent the cylindrical casing whereby, in use, flow of fluid helically along said primary flow path induces a secondary flow of fluid which recirculates from one end of the casing to the other end of the casing between the primary flow and the casing, particulate material moving under centrifugal force from the primary flow to the secondary flow and being deposited at the lower end of the casing. I

2. A device according to claim 1 including a cylindrical baffle sleeve positioned concentrically around the said guide member for guiding said secondary flow, the internal diameter of the sleeve being greater than the diameter of the nozzle mouths, the external diameter of the sleeve being less than the internal diameter of the casing, and the length of the sleeve being maximally equal to the distance between the nozzle mouths. 

1. A device for use in separAting particulate material from a mixture of particulate material and fluid, said device comprising an upstanding cylindrical casing having opposed upper and lower end walls, tubular nozzles projecting one through each of said end walls having a nozzle mouth spaced inwardly from the adjacent end wall of the casing, at least one of said nozzles defining a convergent inlet to the casing, a guide member formed with a cylindrical external surface and extending on and along the longitudinal axis of the casing and entering the mouths of the nozzles peripherally spaced therefrom, said cylindrical external surface of said guide member defining a primary flow path between said nozzles, an oblique inlet conduit offset from the longitudinal axis of the casing and connected to a bottom end wall of the nozzle defining said convergent inlet for directing mixture, when flowing into the casing through the said one of the nozzles defining a convergent inlet to the casing, helically around said guide member and towards the other nozzle along said primary flow path, the mouths of the nozzles being smaller in diameter than the internal diameter of the casing and relatively small dust outlet in the end wall of the casing in which said one of said nozzles defining said convergent inlet extend and being positioned adjacent the cylindrical casing whereby, in use, flow of fluid helically along said primary flow path induces a secondary flow of fluid which recirculates from one end of the casing to the other end of the casing between the primary flow and the casing, particulate material moving under centrifugal force from the primary flow to the secondary flow and being deposited at the lower end of the casing.
 2. A device according to claim 1 including a cylindrical baffle sleeve positioned concentrically around the said guide member for guiding said secondary flow, the internal diameter of the sleeve being greater than the diameter of the nozzle mouths, the external diameter of the sleeve being less than the internal diameter of the casing, and the length of the sleeve being maximally equal to the distance between the nozzle mouths. 